Isis stock zig-zags on test results

The stock price at Isis Pharmaceuticals Inc. (Nasdaq: ISIS) wobbled sharply on Monday and Tuesday on the heels of its announcement of positive test results on its treatment for the hepatitis B virus.

Isis revealed on Monday that that its HBVRx compound produced reductions in all measured liver and serum viral markers of hepatitis B, using animal-based models of infection.

Gaetan Billioud, from the Scripps Research Institute, will unveil the specific data at the 49th annual meeting of the European Association for the Study of the Liver in London next month. In the meantime, Isis is currently evaluating testing HBVRx in a phase 1 study using healthy volunteers.

It was a positive development, but the stock has been on a roller coaster ride ever since. After the announcement was made Monday morning, Isis stock dipped sharply, regained the lost territory by mid-afternoon, rose more in after-hours trading but then dipped again on Tuesday morning so that by noon on Wall Street it was at $42.32, nearly a dollar lower than its level when the announcement was made.

In his “Mad Money” investment show on CNBC, analyst Jim Cramer warned investors not to immediately invest in the stock, because a number of short-sellers -- who had essentially bet on a decline -- were helping push the price down.

“It's a good company, but I wouldn't buy yet,” Cramer said, cautioning investors to wait for an "all clear signal" that the battle between short-sellers and long-term investors was over. “Watch for the stock to go down big ... and then reverse and ultimately go out higher. That's the sign to buy.”

In the meantime, Todd Campbell, president of Gundalow Advisors Wealth Management in New Hampshire, said there is more reason for buying Isis, suggesting that its proposed treatment for vision loss caused by diabetes be able to challenge vision-improvement treatments from Regeneron (Nasdaq: REGN) and Novartis (NYSE: NVS). He noted that Regneron's Eylea had $1.8 billion in sales last year, just two years after winning FDA approval, and sales of Novartis' Lucentis have hit more than $4 billion a year.